非正式沟通网络

据了解，丧子父母通过自己的亲戚、朋友，甚至固定的联系人，来寻找最近丧失单身女儿的家庭。

informal

informal group

the Asia-Pacific Economic Co-operation Economic Leaders Informal Meeting

informal discussion

informal application【专利】

informal style, irregular style

informal test

informal organization